The director of significant new London art gallery Marlborough Contemporary, Dr Andrew Renton, is a collector, as well as being Professor of Curating at Goldsmiths College, University of London. His serene, museum-like London apartment has pictures on the walls, pictures on the floor and pictures on the shelving in between the two. Over the course of his interview with MR PORTER he admits to amassing watches, art, rare records and Subbuteo soccer figurines. As such he's well placed to offer some sage advice for any man thinking of starting an art collection.

I remember not buying one of Damien Hirst's medicine cabinets for £500. Years later someone offered to sell me the same one for £2m

What does it say about the contemporary market that your gallery is opening this season?

It's counterintuitive, I think. It's very brave, it's a big investment and a big commitment, but Marlborough has this sense of a much bigger picture - they've seen Francis Bacon's paintings start at £500, ending up at $100m.

Given such astonishing prices how open is the art world to guys thinking of buying their first work?

It's not just for a privileged elite, art's a much more democratic affair these days. Anyone can roll their sleeves up and become an expert.

Where should a man start if he's thinking of buying his first piece?

The best way to learn about art is to go to see it. You need to see an enormous amount of art, that's the only training for building a collection. You have to hone your instincts.

Does the idea of a collection imply that the works relate to one another?

After you buy your first work, then comes the hard part: you have to set yourself criteria that connects to that first work. You want to build a collection, not just a group of disparate things. Otherwise you end up with a random selection.

What kind of criteria are you thinking of?

You could start a contemporary collection if you bought copies of this month's frieze and Artforum magazines, and built a cookie-cutter wish list of the world's top 10 or 20 artists, before entering that world at whatever price you can afford. That's fine, but it's missing one component - you. A collection should be a narrative; your job is to tell a story that reflects your personality.

What's the best way to invest?

I think the best collections generate their own value. The really amazing collectors lend an identity to the work that they collect. It's the old-fashioned idea of provenance, you can lift a younger artist into the context of more established, successful artists.

Collector's items

The Dub Inventor

A rare King Tubby acetate recording from Dr Renton's dub and reggae collection

desktop artifacts

A postcard of King Tubby. The sound engineer was a pioneer of dub music, whose work is regarded by many as an antecedent of modern dance music

What faith can a collector have in the longevity of video art?

The first generation of video art in the 1960s was so miraculous that no one thought about it, but by now everyone's realised that any medium [such as DVD] is transitional. Increasingly we sell video work with the agreement to migrate to the next technology in due course. I understand that [leading video artist] Bill Viola keeps the master copies of his works in a vault in a nuclear-proof bunker in the desert in America.

How does it work with regard to conceptual art?

A lot of conceptual art from the 1960s was sold on the basis of a certificate, which enabled you to reconstruct the work. But Tino Sehgal, whose work consists of performers engaging with you in a gallery, and shaping your experience of it, and who has been in the Turbine Hall at Tate Modern, decided the certificate was too much, because people fetishise the certificate. If you buy one of his works you go with him to a notary in Paris and exchange there. There's no receipt, no certificate, just a handshake and a witnessing of the exchange. It's a great metaphor for what a collector can be, because it's an act of faith.

Are there any important practical issues to consider?

One of the amazing things about Charles Saatchi, apart from the fact that he's obsessed with the art that he buys, is that he recognised early on that a private collector has to address the issue of storage. Storage is the great enabler, because you can stop thinking about what fits above your sofa. You're a real collector when you've run out of wall space and still buy the next piece.

Does a collector need professional advice?

If you're very serious you should take advice. It's reassuring and it's cheap at the price - whatever you pay your advisor you can probably save by really clarifying the price.

How do you discover the next big thing?

The world is full of artists who had amazing degree shows, but didn't quite fulfil their potential. Instead it's about a local buzz - artists know better than anyone who's good. You have to be asking yourself, will this still be discussed in 10 years; does it tell the story of where art was when it was made?

As a collector have you managed to spot the next big thing?

When Damien Hirst had a show at art school I remember not buying one of his medicine cabinets. He was asking £1,000 for it, but he was going to sell it to me for £500. Many years later someone offered to sell me the same one, and they wanted £2m for it. But the truth was that it wasn't just about Damien Hirst at the time, it was about a group of artists, and none of us could have predicted where it would go.

Have you bought things that don't now look like great investments?

I own some really dodgy stuff. I paid $4,000 for a piece of elastic by a Belgian artist called Joëlle Tuerlinckx. It's a piece of elastic that attaches to the ceiling and it's got a bit of felt pen in the middle and it's held on the ground by a weight. One of these days the elastic will perish.

What is it about reggae that inspires you to collect it?

I'm particularly interested in one-off acetates and dub plates. King Tubby's my hero, he made hundreds if not thousands of tracks - so often with these tracks you have a version that no one else has. There's an artisanal quality to the Jamaican stuff, the sleeves were screened by hand, the labels were hand stamped, so it has a really physical quality.

Marlborough Contemporary opens on 12 October with an exhibition by Ms Ângela Ferreira, Stone Free, which runs until 17 November. marlboroughcontemporary.com